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What is happening to the Jamaican climate?
Climate Studies Group, Mona (CSGM)Department of Physics
University of the West Indies, Mona
Climate Change and Jamaica: Why worry?
RAIN A FALL, BUT DUTTY TUFF
Climate Context
3
Part 1
1. CLIMATE CONTEXT
ClimatologyAverage behaviour of weather
Examine values of a number of climate variables Temperature Rainfall Solar Radiation Wind Relative Humidity
RAIN A FALL . . . . .
1. CLIMATE CONTEXT
Temperature Varies with earth’s orbit
about the sun
Hotter in summer (July‐August)
Range of 3˚C
Spatial variation in mean temperature across island
Jamaica
Manley
Sangster
RAIN A FALL . . . . .
1. CLIMATE CONTEXT Rainfall
Bimodal
Early season: May‐July Late season: August – November‐ coincides with peak hurricane season
Mean no. of rain days: 60‐200 days
RAIN A FALL . . . . .
1. CLIMATE CONTEXT Rainfall Spatial variability
across the island. Max in Portland
(Centre of max is only approximate)
Rainfall Means
1. CLIMATE CONTEXT Solar Estimated average of 177 MJ/ m2 per year of direct solar radiation.
Very slight variation from north to south
Indication of slightly higher values in the far eastern tip of Jamaica.
Mean global radiation across Jamaica
1. CLIMATE CONTEXT Wind Combination of prevailing
winds, sea breezes and mountain and valley winds
Prevailing winds from east or northeast is strongest influence
Driest months = larger wind speeds
Wettest month = smaller wind speeds
Modelled wind speed over Jamaica based on data collected at Manley and Sangster Airports and at Munro
1. CLIMATE CONTEXT
Other Variables Relative humidity does not
vary significantly throughout the year.
Sunshine hours vary little throughout the year, ranging between 7 and 9 hours per day. More sunlight hours in
the dry season and less in the main rainy season
Evaporation values peak approaching July
Norman Manley International Airport
Relative Humidity (%) Evaporation Sunshine Hours
(hrs)7am 1pm
January 76.94 60.31 5.92 8.37
February 76.50 60.69 6.75 8.75
March 75.50 61.13 7.59 8.65
April 72.87 61.47 7.96 9.10
May 73.40 64.67 7.76 8.03
June 72.08 63.08 8.53 7.94
July 71.93 61.73 8.47 8.13
August 73.73 64.93 7.85 7.90
September 75.33 65.93 6.98 7.36
October 77.31 66.88 6.99 7.49
November 77.07 63.75 6.03 7.87
December 77.63 61.19 5.89 7.94
Annual 75.02 62.98 7.23 8.13
1. CLIMATE CONTEXT Hurricanes Easterly waves frequently mature into storms and hurricanes
June ‐ November
Hurricane tracks for 1851-2010
QUICK REVIEW
Which 4 of the following are features of Jamaica’s climate?
12
Hotter in summer Greater wind speeds in drier
months
Hurricane in April Relative Humidity does not vary a lot
Same amount of rainfall over entire
island
Early & Late rainfall seasons
QUICK REVIEW
Which 4 of the following are features of Jamaica’s climate?
13
Hotter in summer Greater wind speeds in drier
months
Relative Humidity does not vary a lot
Early & Late rainfall seasons
YU NEBBA SEE SUMOKE WIDOUT FIYAH
Climate Change Observed
14
Part 2
2. CLIMATE CHANGE OBSERVED
Higher Temperatures Globe Caribbean Jamaica
0.1 degrees Celsius/decade for airports
0.27 degrees Celsius/decade for island
Percent of very warm days and very warm nights observed annually increasing
YU NEBBA SEE SUMOKE. . . . .
2. CLIMATE CHANGE OBSERVED
Variable Rainfall
Significant interannual(year to year) variability
Decadal variability Last decade shows
rainfall trending upwards
Mean Jamaica rainfall record shows no statistically significant trend
Jamaican rainfall (blue) with decadal trends (red)
YU NEBBA SEE SUMOKE. . . . .
2. CLIMATE CHANGE OBSERVED
Variable Rainfall
Significant decrease in theproportion of total rainfall that occurs in ‘heavy’ events
Increasing rainfall over the centre of the island and decreasing rainfall over the eastern and western parishes
Map showing Rainfall trends slope. Positive slope suggest increasing rainfall, and negative slope suggest decreasing rainfall
YU NEBBA SEE SUMOKE. . . . .
2. CLIMATE CHANGE OBSERVED
Higher Sea Levels Global sea level rise over the 20th century is estimated to have been
0.17 ± 0.05 m.
Caribbean appears to be near the global mean
Port Royal between 1955 and 1971 also indicate a 0.9 mm/year rising trend (Horsfield, 1973).
Mean annual sea levels at Port Royal measured between 1955 and 1971.
2. CLIMATE CHANGE OBSERVED
Tidal Gauge Station Observed Trend (mm/yr)
Observation Period
Bermuda 2.04 ± 0.47 1932 – 2006
San Juan, Puerto Rico
1.65 ± 0.52 1962 – 2006
Guantanamo Bay, Cuba
1.64 ± 0.80 1973 – 1971
Miami Beach, Florida
2.39 ± 0.43 1931 – 1981
Vaca Key, Florida 2.78 ± 0.60 1971 – 2006
2. CLIMATE CHANGE OBSERVED
Higher Hurricane Frequency since 1995.
May be attributed to Atlantic multidecadal oscillation and not necessarily due to global warming (Goldenburg et al., 2001).
Additionally El Niño and La Niña events influence the location and activity of tropical storms across the globe.
2. CLIMATE CHANGE OBSERVED
Other Variables Significant increases in the annual and seasonal values of wind
speed around Jamaica in all seasons over the period 1960‐2006 No significant trend in Relative Humidity (RH) over Jamaica
Observed trends for 1960-2006
Variable Annual
DJF MAM JJA SON
Wind Speed (ms‐1) 0.26 0.27 0.25 0.27 0.25Relative Humidity (%) 0.03 0.19 ‐0.06 0.09 ‐0.11
Sunshine Hours (hrs) 0.28 0.19 0.78 0.4 ‐0.26Sea surface temperatures( oC/decade)
0.04 0.01 0.02 0.07 0.07
2. CLIMATE CHANGE OBSERVED
Other Variables Statistically significant increases in sunshine hours in MAM and
JJA for Jamaica over recent years (1983‐2001). Statistically significant increasing trends in JJA and SON sea
surface temperatures
Observed trends for 1960-2006
Variable Annual
DJF MAM JJA SON
Wind Speed (ms‐1) 0.26 0.27 0.25 0.27 0.25Relative Humidity (%) 0.03 0.19 ‐0.06 0.09 ‐0.11
Sunshine Hours (hrs) 0.28 0.19 0.78 0.4 ‐0.26Sea surface temperatures( oC/decade)
0.04 0.01 0.02 0.07 0.07
QUICK REVIEW: CLIMATE CHANGEOBSERVED
Temperature
Rainfall
Sea Level
Hurricane Frequency
Sunshine Hours
Wind speed
Relative Humidity
Getting Higher
Getting Lower
No significant Trend
23
A NUH SAME DAY LEAF DROP
A RIVER BOTTOM IT ROTTEN
More Climate Change Expected
24
Part 3
25
Models
GCMs or RCMs
Scenarios
A2A1BB2
Future Climate
TemperatureRainfall
Sea Level Rise, etc.
Reminder of how we get projections
CLIMATE CHANGE EXPECTED
MORE CLIMATE CHANGE EXPECTED
Jamaica on GCM grid
Jamaica on RCM grid
26
Key take home points
GCMS Lots of GCMs (21 ensemble) – good
for range GCMs have lots of climate variables GCMs give one value for Jamaica
RCM One RCM – PRECIS but forced by 2
GCMs and 2 scenarios – still have range
Has 12 grid boxes for Jamaica (50 km)
Lots of climate variables Right now end of century only
PROJECTIONS OF TEMPERATURE…
21 member ensemble Caribbean expected
to warm 1.4 ‐3.2 degrees by 2100
Greatest in SON 100% of days at end
of century warmer than present
27
IPCC 2007
Caribbean context from GCMs
A NUH SAME DAY. . . . .
15 member ensemble
Mean warming 1.1 ‐ 3.5 degrees by the 2090s
Extremes 30‐98% of days annually will be
considered ‘hot’ by the 2090s
Only 2% ‘cool’ by the 2080s Most change in summer months
(JJA)
28
McSweeney et al. 2008
PROJECTIONS OF TEMPERATURE…Jamaica from GCMs
Mean Temps
Warm Days
Cool Nights
A NUH SAME DAY. . . . .
Warming by 12 grid boxes Warming by month, season and annually
29
PROJECTIONS OF TEMPERATURE…Jamaica from RCMs
CSGM 2012
A2GRID_1 GRID_2 GRID_3 GRID_4 GRID_5 GRID_6 GRID_7 GRID_8 GRID_9 GRID_10 GRID_11 GRID_1
2JAN 2.56 2.31 4.41 4.32 3.38 3.55 2.82 2.28 3.00 2.45 2.22 2.22FEB 2.63 2.51 3.90 3.90 4.14 4.29 3.14 2.49 2.91 2.47 2.23 2.20MAR 2.67 2.71 3.51 3.61 4.20 4.42 3.53 2.75 2.96 2.67 2.47 2.42APR 2.62 2.76 3.16 3.35 3.50 3.89 3.45 2.87 2.97 2.84 2.72 2.67MAY 2.49 2.67 4.18 4.48 4.37 4.41 3.46 2.86 3.43 3.14 2.98 2.95JUN 2.58 2.72 5.29 5.56 5.17 5.00 3.81 2.90 3.95 3.51 3.37 3.38JUL 2.55 2.44 5.97 6.10 5.14 4.94 3.74 2.50 3.98 3.42 3.32 3.40AUG 2.34 1.85 5.42 5.25 4.92 4.79 3.47 1.78 3.33 2.82 2.85 3.00SEP 2.20 1.47 5.58 5.65 4.99 4.81 3.35 1.38 3.11 2.49 2.44 2.61OCT 2.13 1.49 5.52 6.24 4.80 4.85 3.33 1.49 3.12 2.51 2.31 2.43NOV 2.27 1.81 4.70 5.45 3.59 3.65 2.85 1.85 3.00 2.58 2.39 2.47DEC 2.45 2.10 4.55 4.86 3.21 3.27 2.76 2.11 3.03 2.56 2.37 2.41ANN 2.46 2.24 4.68 4.90 4.28 4.32 3.31 2.27 3.23 2.79 2.64 2.68NDJ 2.43 2.07 4.55 4.88 3.39 3.49 2.81 2.08 3.01 2.53 2.33 2.37FMA 2.64 2.66 3.52 3.62 3.95 4.20 3.37 2.70 2.95 2.66 2.47 2.43MJJ 2.54 2.61 5.15 5.38 4.89 4.79 3.67 2.75 3.79 3.36 3.22 3.24ASO 2.22 1.60 5.51 5.71 4.90 4.82 3.38 1.55 3.18 2.61 2.53 2.68
A NUH SAME DAY. . . . .
Warming by west (grid boxes 2,3 8, 9); centre (1,4,5,10, 11); east (6)
Warming by month, season and annually
30
PROJECTIONS OF TEMPERATURE…Jamaica from RCMs
CSGM 2012
MTH WEST CENTRE EAST JAMAICA
A2 B2 A2 B2 A2 B2 A2 B2
JAN 3.0 2.3 3.0 2.2 3.6 2.2 3.0 2.2
FEB 3.0 2.1 3.1 2.1 4.3 2.4 3.1 2.1
MAR 3.0 2.2 3.1 2.4 4.4 3.4 3.2 2.4
APR 2.9 2.1 3.0 2.3 3.9 2.8 3.1 2.2
MAY 3.3 2.3 3.5 2.5 4.4 2.8 3.5 2.4
JUN 3.7 2.6 4.0 2.8 5.0 3.0 3.9 2.7
JUL 3.7 2.8 4.1 3.0 4.9 3.0 4.0 2.9
AUG 3.1 2.7 3.6 2.8 4.8 2.9 3.5 2.7
SEP 2.9 2.6 3.6 2.8 4.8 3.0 3.3 2.7
OCT 2.9 2.5 3.6 2.7 4.8 2.7 3.4 2.6
NOV 2.8 2.4 3.3 2.5 3.7 2.3 3.1 2.4
DEC 2.9 2.4 3.1 2.4 3.3 2.3 3.0 2.3
A NUH SAME DAY. . . . .
Warming expected across the island 2.9˚C and 3.4˚C by the 2080s
Greatest warming in JJA (up to 5 degrees warmer than present)
Some areas may warm faster than others e.g. south and east
31
CSGM 2012
PROJECTIONS OF TEMPERATURE…Jamaica from RCMs
Figure 7.2.1
QUICK REVIEW
What do we expect to happen to temperatures over Jamaica towards the end of the century?
32
1. Increase
2. Decrease
3. No change
4. Still unsure (No consensus)
QUICK REVIEW
What do we expect to happen to temperatures over Jamaica towards the end of the century?
33
1. Increase
21 member ensemble
Drying across the Caribbean Basin Most models
agree ‐39% to +11% by
end of century Minimal interannual
variability
34
IPCC 2007
PROJECTIONS OF RAINFALL…Caribbean context from GCMs
‐44% to +18% by the 2050s and ‐55% to +18% by the 2080s
Drier JJA (early wet season) and SON (late wet season)
35
McSweeney et al. 2008
PROJECTIONS OF RAINFALL…Jamaica from GCMs
15 member ensemble
Rainfall extremes: Mixed across the
ensemble. Tendency for
decreases in rainfall extremes.
36
McSweeney et al. 2008
PROJECTIONS OF RAINFALL…Jamaica from GCMs
Figure 6.4.2a & Table 6.4.2
McSweeney et al. 2008
% changes by 12 grid boxes % changes by month, season and annually
37
PROJECTIONS OF RAINFALL…Jamaica from RCMs
A2 GRID_1 GRID_2 GRID_3 GRID_4 GRID_5 GRID_6 GRID_7 GRID_8 GRID_9 GRID_10 GRID_11 GRID_12
JAN ‐30.9 ‐42.0 ‐50.9 ‐54.5 ‐38.3 ‐37.3 ‐23.5 ‐45.6 ‐43.3 ‐60.1 ‐51.8 ‐48.7FEB ‐13.6 20.5 ‐6.7 ‐19.1 ‐17.3 ‐25.9 ‐22.0 ‐15.3 5.4 ‐42.6 ‐43.2 ‐38.6MAR 19.7 46.8 29.0 19.3 6.5 ‐13.7 ‐10.7 14.3 9.9 ‐21.5 ‐36.1 ‐30.3APR 7.9 62.6 37.6 22.3 9.0 ‐5.9 ‐8.3 37.0 67.3 ‐3.0 ‐5.2 ‐6.7MAY ‐63.7 ‐61.4 ‐51.4 ‐58.0 ‐50.7 ‐48.0 ‐41.4 ‐59.3 ‐39.3 ‐71.4 ‐71.8 ‐58.0JUN ‐78.4 ‐77.8 ‐74.6 ‐78.3 ‐65.9 ‐59.2 ‐53.9 ‐76.0 ‐51.6 ‐71.6 ‐57.5 ‐60.9JUL ‐70.2 ‐73.5 ‐72.3 ‐74.8 ‐57.5 ‐52.7 ‐49.8 ‐84.0 ‐53.6 ‐65.5 ‐23.3 ‐30.7AUG ‐73.1 ‐67.2 ‐64.9 ‐65.9 ‐52.6 ‐42.4 ‐39.3 ‐84.1 ‐61.5 ‐60.8 10.0 ‐10.1SEP ‐75.6 ‐73.0 ‐72.8 ‐79.3 ‐62.1 ‐47.9 ‐42.5 ‐88.0 ‐76.2 ‐75.4 ‐34.0 ‐41.1OCT ‐74.5 ‐78.4 ‐66.8 ‐78.7 ‐68.5 ‐66.0 ‐58.9 ‐84.1 ‐76.4 ‐82.5 ‐77.7 ‐77.1NOV ‐52.2 ‐61.3 ‐42.0 ‐55.9 ‐41.3 ‐51.8 ‐44.5 ‐62.6 ‐58.4 ‐77.1 ‐77.7 ‐69.1DEC ‐73.1 ‐77.6 ‐66.5 ‐71.2 ‐54.6 ‐56.2 ‐45.5 ‐69.1 ‐70.0 ‐78.9 ‐78.6 ‐66.5ANN ‐63.2 ‐62.9 ‐57.9 ‐64.4 ‐51.5 ‐48.6 ‐42.1 ‐66.3 ‐51.9 ‐67.0 ‐63.9 ‐54.2NDJ ‐58.2 ‐65.5 ‐50.7 ‐60.6 ‐45.3 ‐51.3 ‐41.7 ‐63.0 ‐60.8 ‐75.7 ‐75.2 ‐64.8FMA 5.8 45.5 25.2 11.1 1.4 ‐13.4 ‐12.6 12.2 28.6 ‐23.7 ‐30.5 ‐25.4MJJ ‐70.3 ‐69.0 ‐66.1 ‐70.1 ‐58.0 ‐53.3 ‐48.3 ‐70.6 ‐46.8 ‐70.3 ‐65.2 ‐53.9ASO ‐74.5 ‐75.3 ‐68.2 ‐76.0 ‐62.4 ‐53.2 ‐47.6 ‐85.2 ‐73.1 ‐77.2 ‐63.1 ‐58.9
CSGM 2012
May onward projected to get drier, irrespective of scenario or area Models agree that JJA will get drier by end of century East‐ throughout the year
Toggle between west and east in dry months and wet months
38
PROJECTIONS OF RAINFALL…Chapter 7: Jamaica from RCMs
CSGM 2012
MTHWEST CENTRE EAST JAMAICA
A2 B2 A2 B2 A2 B2 A2 B2
JAN ‐45.4 ‐25.0 ‐47.1 ‐17.8 ‐37.3 ‐8.3 ‐43.9 ‐18.6
FEB 1.0 4.6 ‐27.2 ‐13.2 ‐25.9 ‐9.5 ‐18.2 ‐6.5
MAR 25.0 ‐21.8 ‐2.4 ‐37.2 ‐13.7 ‐35.3 2.8 ‐32.3
APR 51.1 30.6 6.2 8.7 ‐5.9 ‐0.2 17.9 14.1
MAY ‐52.8 ‐14.8 ‐63.1 ‐12.5 ‐48.0 ‐9.7 ‐56.2 ‐11.8
JUN ‐70.0 ‐42.8 ‐70.3 ‐37.0 ‐59.2 ‐25.4 ‐67.1 ‐35.1
JUL ‐70.8 ‐55.0 ‐58.3 ‐40.0 ‐52.7 ‐23.1 ‐59.0 ‐38.7
AUG ‐69.4 ‐56.3 ‐48.5 ‐36.3 ‐42.4 ‐14.7 ‐51.0 ‐35.9
SEP ‐77.5 ‐61.8 ‐65.3 ‐46.7 ‐47.9 ‐26.6 ‐64.0 ‐45.8
OCT ‐76.4 ‐51.3 ‐76.4 ‐60.0 ‐66.0 ‐42.5 ‐74.1 ‐54.0
NOV ‐56.1 ‐25.0 ‐60.8 ‐43.7 ‐51.8 ‐34.5 ‐57.8 ‐36.0
DEC ‐70.8 ‐45.8 ‐71.3 ‐53.3 ‐56.2 ‐40.5 ‐67.3 ‐47.8
Most severe in the west and least severe in Portland in annual
39
A2 B2
CSGM 2012
PROJECTIONS OF RAINFALL…Jamaica from RCMs
QUICK REVIEW
What do we expect to happen to summer rainfall over Jamaica towards the end of the century?
40
1. Increase
2. Decrease
3. No change
4. Still unsure (No consensus)
QUICK REVIEW
What do we expect to happen to summer rainfall over Jamaica towards the end of the century?
41
2. Decrease
May not be representative of Jamaica in GCMs Small increases‐ DJF, MAM
RCMs General decrease
throughout the year‐greatest in JJA
‐1.1 to ‐1.7% by the 2080s under A2
42
PROJECTIONS OF OTHER VARIABLES…Relative Humidity for Jamaica from RGCMs & RCMs
CSGM 2012
GCMs No consensus May increase
RCMs Decreases in wind speed by 2080s under A2 Greatest in SON by ‐0.3 to ‐0.5 ms‐1
43
PROJECTIONS OF OTHER VARIABLES…Wind speeds for Jamaica from RGCMs & RCMs
GCMs Most models suggest increase in sunshine hours under A2
‐0.2 to +0.9 hours per day Greatest in JJA
Higher sea surface temperatures (SSTs) +0.9˚C and +2.7˚C by the 2080s Greatest in SON
RCMs Changes in sunshine hours surpass GCM projections
Increase by +1.4 hours per day by 2080s under A2
No SST projections from RCMs
44
PROJECTIONS OF OTHER VARIABLES…Sunshine hours and sea surface temperatures for Jamaica from RGCMs & RCMs
CARIBSAVE Climate Change Risk Atlas – Jamaica (2011)
Difficult to project for the region
Increase in rainfall intensity associated with tropical storms
Storm surges could intensify if hurricanes become more intense and sea levels rise
0.18‐0.59m by 2100 relative to 1980s to 1990s
45
Bender et al., 2010 After Hansen, 2007
PROJECTIONS OF OTHER VARIABLES…Hurricanes and Sea Level Rise from GCMs
QUICK REVIEW
Which of the following variables are expected to increase towards the end of the century?
46
1. Sunshine Hours
2. Relative Humidity
3. Sea Level Rise
4. Rainfall intensity associated with tropical storms
5. Sea Surface Temperatures
6. Wind speeds
QUICK REVIEW
Which of the following variables are expected to increase towards the end of the century?
47
1. Sunshine Hours
3. Sea Level Rise
4. Rainfall intensity associated with tropical storms
5. Sea Surface Temperatures
48
PROJECTIONS…Jamaica from GCMs and RCMs
2020s 2050s 2080s
Annual T (oC) +0.65 ‐ +0.85 +1.16 ‐ +1.83 +1.55 ‐ +3.52Pcp (%) ‐7.85 ‐ +19.51 ‐10.61 ‐ +10.70 ‐55.60 ‐ +16.49
NDJ T (oC) +0.58 ‐ +0.93 +0.96 ‐ +1.82 1.42 ‐ 3.15Pcp (%) ‐3.07 ‐ +18.43 ‐11.68 ‐ +22.58 ‐55.09 ‐ +16.97
FMA T (oC) +0.62 ‐ +0.88 +1.12 ‐ +1.76 +1.47 ‐ +3.18Pcp (%) ‐15.20 ‐ +48.19 ‐13.22 ‐ +19.53 ‐22.87 ‐ +24.00
MJJ T (oC) +0.57 ‐ +1.03 +1.16 ‐ +1.85 +1.73 ‐ +4.00Pcp (%) ‐32.24 ‐ +23.62 ‐29.9 ‐ ‐2.09 ‐60.43 ‐ ‐1.18
ASO T (oC) +0.73 ‐ +0.93 +1.16 ‐ +1.96 +1.58 ‐ +3.70Pcp (%) ‐9.8 ‐ +37.92 ‐16.63 ‐ +32.92 ‐66.79 ‐ +33.42
THE TAYLOR TRUTH (SUMMARIZED)
Jamaica’s climate has changed.Jamaica’s climate will continue to change.
Jamaica’s climate demands change
49